Climate disruption is elementary physics: more heat plus more water in the atmosphere equals more severe weather. Climate change will cost our economy between $44 to $74 Trillion over the next 25 years if left unchecked according to Citigroup study published in November 2015.

Tom Harris has an engineering background. He should be able to appreciate the following fundamental principles of physics.

Except at the temperatures of absolute zero (minus-273.15 degrees C), molecules are always in motion because they have innate energy at the subatomic level.

When one applies heat energy to a system, molecules move faster. To convince yourself, put food colouring in cold water and hot water, then compare how fast the food colouring moves through the two temperatures of water.

Why is this important to know? Because the energy of water molecules moving and heat energy in the atmosphere are two driving forces behind extreme weather such as tornadoes and hurricanes.

Scientists have known for almost 200 years that carbon dioxide, a byproduct of burning fossil fuels, traps heat energy in the Earth’s atmosphere. It is also known that the more heat trapped in the atmosphere, the more water it holds.

Thus, by burning fossil fuels, we are adding heat energy and the energy of more water molecules moving in our atmosphere.

According to Dr. James Hansen, humans are putting the equivalent of 400,000 Hiroshima bombs worth of energy into the atmosphere every day. In November 2015, humanity passed an ominous milestone: the last time anyone alive will experience global carbon dioxide (C02) levels below 400 ppm.The scientific data strongly suggests that the safe level is 350 ppm.

For more than 10,000 years of human civilization, until the last 100 years, atmospheric C02 was below 300 ppm.

The last time global C02 was over 400 ppm was more than three million years ago, and the oceans’ sea level ranged between five and 40 meters higher than today.

It is not just the level of C02 that is of concern; it is also the rate at which it is rising. During the last 150 years, humans have increased the Earth’s C02 levels from 280 ppm to 400 ppm. The last time the Earth’s C02 rose this quickly was during the Paleocene-Eocene Thermal Maximum (PETM), 55 million years ago.

The geological record of the PETM tells a harrowing tale of massive global climate disruption and extinction because positive feedback loops kicked in over a very short time period and the Earth heated up faster than animals and plants could adapt.

Humanity has unleashed climate disruption upon our only home — Earth.

However, if we unleash the power of the free market with a price on dangerous carbon pollution we can transition to a low-carbon economy with relative ease.

Ignoring climate change will have profound negative effects on the economy, which would be immoral to ignore.

In Canada, we cherish freedom of the press. Our local media holds the feet to the fire of the politicians when they are not doing their job — such as protecting us from threats such as the climate crisis.

I live in a city, Sudbury, Ont., where my local media accepts the science of climate change. Our two local papers stopped publishing letters from Tom Harris long ago. A quick Internet search might help you understand why.